Update default version to new Node LTS version v10.x (#581)

* Update default version to new Node LTS version v10.x

lib/binaries.sh

@@ -27,7 +27,7 @@ install_yarn() {
 }
 
 install_nodejs() {
-  local version=${1:-8.x}
+  local version=${1:-10.x}
   local dir="${2:?}"
 
   echo "Resolving node version $version..."

test/fixtures/ci-dependencies-yarn/package.json

@@ -11,7 +11,7 @@
   },
   "license": "MIT",
   "engines": {
-    "yarn": "1.4.0"
+    "yarn": "1.x"
   },
   "devDependencies": {
     "lodash": "^2.4.1"

test/fixtures/dependencies-yarn/package.json

@@ -11,7 +11,7 @@
   },
   "license": "MIT",
   "engines": {
-    "yarn": "1.4.0"
+    "yarn": "1.x"
   },
   "devDependencies": {
     "lodash": "^2.4.1"

test/fixtures/node-env-consistency/package.json

@@ -4,7 +4,7 @@
   "main": "index.js",
   "license": "MIT",
   "engines": {
-    "npm": "5.5.1"
+    "npm": "6.x"
   },
   "scripts": {
     "heroku-prebuild": "echo 'heroku-prebuild:' $NODE_ENV",

test/run

@@ -11,8 +11,8 @@
 testNoVersion() {
   compile "no-version"
   assertCaptured "engines.node (package.json):  unspecified"
-  assertCaptured "Resolving node version 8.x"
-  assertCaptured "Downloading and installing node 8."
+  assertCaptured "Resolving node version 10.x"
+  assertCaptured "Downloading and installing node 10."
   assertCapturedSuccess
 }